It has long been recognized that detection of certain gases is necessary for the safety or well-being of human life. Indeed, coal miners used the canary to warn them of the presence of life endangering gases. The art has progressed until today there are many systems of gas detection, i.e., infrared, gas chromatography, etc. These systems to date, have required costly and elaborate equipment and reference materials to be reliable. One primary use for such a detection system has been its installation in vehicles to attempt to detect the presence of breath alcohol, i.e., ethanol, in the exhalation of the driver.
In the field of chromatography as used for gaseous detection, the conventional arrangement requires a pure gas to be used as the carrier of the sample being tested. This requires a source of pure gas to be readily available wherever and whenever the gas detection equipment is to be used. Infrared detection of gases requires a source of infrared spectrum including a power source which does not lend itself to economical usage of equipment.
There is therefore a need for simple, economical and reliable equipment and a process to detect individual gases accurately, both as to presence and quantity.
It has long been recognized that driving a motor vehicle while under the influence of alcohol constitutes a serious problem for society. This practice has been statistically shown to contribute to a great loss of life, limb and property, and such losses are not limited to only those individuals who incur the risk by driving while intoxicated. Many laws have been passed by various states in an attempt to control this situation. Such laws provide for a variety of penalties, including fines, prison terms and loss of driving privileges, as well as requiring reeducation regarding safe and proper driving practices. Though such laws no doubt aid in preventing some abuses, these actions do not represent a completely adequate solution.
In the early 1970's, the National Highway Traffic Safety Administration sought to encourage development of an alcohol safety interlock system for use with motor vehicles. Simply described, the Administration sought a device that would reliably detect the presence of an intoxicated driver behind the wheel of a vehicle, and prevent the vehicle from being driven. One way of accomplishing the latter was to disable the ignition.
Certain disadvantages are associated with such a system. For instance, the vehicle cannot be used in an emergency, may present a danger to other traffic in the vicinity, and there is a problem with general public acceptability. Because of these problems, the alcohol safety interlock system failed to lead to a generally acceptable and useful device.
Efforts were then made to develop a system that would provide warnings that an intoxicated person was driving a particular motor vehicle. One particular system constructed required the driver to pass a brief test using the steering wheel before the vehicle could be driven in a normal manner. That device has failed to adequately detect intoxication and has been abandoned by the government. There still remain a number of problems with any system making the intoxication determination dependent upon an impairment test. Error presents a serious concern.
There therefore still exists a need for a vehicle alcohol detection warning system that will reliably detect the presence of an intoxicated driver, i.e., one with a predetermined breath alcohol level and that will provide not only a recordable evidentiary quality determination of such breath alcohol level, but also a socially acceptable, yet easily noticeable warning to the public and to law enforcement officials that the driver of the vehicle in question probably is intoxicated. Such a system should be easily manufactured, durable of construction and relatively inexpensive. Further, such a system should be relatively simple to install in a motor vehicle. Additionally, such a system must be senstive only to breath alcohol level, i.e., ethanol. The prior art has been unable to distinguish between ethanol and other gases, and therefore has proved ineffective for detection purposes.